Death May Be Your Santa Claus comes from a song on Mott the Hoople's album Brain Capers (1971). Quoth Stephen Thomas Erlewine on the All-Music Guide: All these changes are evident from the moment Brain Capers kicks in with the monumental "Death May Be Your Santa Claus," a phenomenally pile-driving number that just seems inevitable.
What he said. Amusingly enough, the phrase "Death May Be Your Santa Claus" appears nowhere in the song's lyrics.
Death May Be Your Santa Claus is also a movie, accordingto the Internet Movie Database, but I have not seen it.